5.11 Real Time Clock (RTC)
MIPS® Malta™ User’s Manual, Revision 01.07 39
Copyright © 2000-2007 MIPS Technologies Inc. All rights reserved.
5.11 Real Time Clock (RTC)
The South Bridge (U9) contains the Real Time Clock for the board [6]. The clock has an external battery backup
(CR2032 coin cell) (J10), which has an expected life time of 5-10 years.
5.12 IDE/CompactFlash (True IDE Mode)
The South Bridge (U9) provides both primary and secondary IDE busses [6]. The primary bus is brought out on con-
nector J18, and may have both master and slave devices attached. The secondary bus connects both to the Compact
Flash connector J20 (Type I or II connector) and to the secondary IDE connector J19. Jumper JP3 selects whether the
Compact Flash module behaves as (if fitted) a master or (if not fitted) as a slave device. If a Compact Flash module is
used, any device plugged into the secondary IDE connector must have the opposite setting.
For additional information about Compact Flash modules, see [15].
5.13 Flash Memory
Malta is fitted with 4 Mbytes of Flash memory (refered to as Monitor Flash), which is used to boot the system. See
Chapter 3, “Memory Map” on page 13 for details of the Malta memory map.
The Monitor Flash can be programmed via a download cable, as described in Chapter 6, “1284 Flash Download
Format” on page 45.
The Monitor Flash can also be reprogrammed by software. There is one protection mechanism:
• Jumper JP1 (See Section 4.1, "Connectors & Jumpers") must be installed for any writing to the Monitor Flash
Lock Bits from software.
Note that while the Monitor Flash is being reprogrammed by software, the code that performs the reprogramming
will have to be copied into RAM and executed there, because the Flash is inaccessible during this process.
All the Flash fitted are Intel 16 Mbit FlashFile devices. See Intel’s web site for the documentation, or see YAMON
documentation [3] for an easy-to-use software interface.
From a hardware viewpoint, the Flash appears as a 32-bit wide block, with no individual write control capability to
allow writing to just one, 16-bit halfword. However, this function can be achieved by software by running a
Read-Modify-Write cycle.
5.14 EEPROM
The I
2
C-connected EEPROM (U14) contains, on manufacture, the board serial number. The remaining locations in
the EEPROM are not available for application use.
A second EEPROM (U39) is directly connected to the Ethernet controller and is used to store the board’s MAC
address.
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